diff --git a/pkg/sql/schema_change_plan_node.go b/pkg/sql/schema_change_plan_node.go
index dfd4750cb3ac..f232d9b66e7c 100644
--- a/pkg/sql/schema_change_plan_node.go
+++ b/pkg/sql/schema_change_plan_node.go
@@ -181,8 +181,8 @@ func (p *planner) waitForDescriptorSchemaChanges(
 	ctx context.Context, descID descpb.ID, scs SchemaChangerState,
 ) error {
 
-	if knobs := p.ExecCfg().DeclarativeSchemaChangerTestingKnobs; knobs != nil &&
-		knobs.BeforeWaitingForConcurrentSchemaChanges != nil {
+	knobs := p.ExecCfg().DeclarativeSchemaChangerTestingKnobs
+	if knobs != nil && knobs.BeforeWaitingForConcurrentSchemaChanges != nil {
 		knobs.BeforeWaitingForConcurrentSchemaChanges(scs.stmts)
 	}
 
@@ -196,7 +196,6 @@ func (p *planner) waitForDescriptorSchemaChanges(
 	// Wait for the descriptor to no longer be claimed by a schema change.
 	start := timeutil.Now()
 	logEvery := log.Every(10 * time.Second)
-	var wasBlocked bool
 	for r := retry.StartWithCtx(ctx, base.DefaultRetryOptions()); r.Next(); {
 		now := p.ExecCfg().Clock.Now()
 		var isBlocked bool
@@ -215,9 +214,7 @@ func (p *planner) waitForDescriptorSchemaChanges(
 		}); err != nil {
 			return err
 		}
-		if isBlocked {
-			wasBlocked = true
-		} else {
+		if !isBlocked {
 			break
 		}
 		if logEvery.ShouldLog() {
@@ -226,11 +223,9 @@ func (p *planner) waitForDescriptorSchemaChanges(
 					" waited %v so far", descID, timeutil.Since(start),
 			)
 		}
-	}
-
-	if knobs := p.ExecCfg().DeclarativeSchemaChangerTestingKnobs; knobs != nil &&
-		knobs.AfterWaitingForConcurrentSchemaChanges != nil {
-		knobs.AfterWaitingForConcurrentSchemaChanges(scs.stmts, wasBlocked)
+		if knobs != nil && knobs.WhileWaitingForConcurrentSchemaChanges != nil {
+			knobs.WhileWaitingForConcurrentSchemaChanges(scs.stmts)
+		}
 	}
 
 	log.Infof(
diff --git a/pkg/sql/schemachanger/scexec/testing_knobs.go b/pkg/sql/schemachanger/scexec/testing_knobs.go
index 684318390ece..bd3d7fd65f20 100644
--- a/pkg/sql/schemachanger/scexec/testing_knobs.go
+++ b/pkg/sql/schemachanger/scexec/testing_knobs.go
@@ -27,9 +27,9 @@ type TestingKnobs struct {
 	// for concurrent schema changes to finish.
 	BeforeWaitingForConcurrentSchemaChanges func(stmts []string)
 
-	// AfterWaitingForConcurrentSchemaChanges is called at the end of waiting
+	// WhileWaitingForConcurrentSchemaChanges is called while waiting
 	// for concurrent schema changes to finish.
-	AfterWaitingForConcurrentSchemaChanges func(stmts []string, wasBlocked bool)
+	WhileWaitingForConcurrentSchemaChanges func(stmts []string)
 
 	// OnPostCommitPlanError is called whenever the schema changer job returns an
 	// error on building the state or on planning the stages.
diff --git a/pkg/sql/schemachanger/schemachanger_test.go b/pkg/sql/schemachanger/schemachanger_test.go
index 0c5736519533..3cec12adce61 100644
--- a/pkg/sql/schemachanger/schemachanger_test.go
+++ b/pkg/sql/schemachanger/schemachanger_test.go
@@ -100,9 +100,9 @@ func TestConcurrentDeclarativeSchemaChanges(t *testing.T) {
 	params, _ := tests.CreateTestServerParams()
 	params.Knobs = base.TestingKnobs{
 		SQLDeclarativeSchemaChanger: &scexec.TestingKnobs{
-			AfterWaitingForConcurrentSchemaChanges: func(stmts []string, wasBlocked bool) {
+			WhileWaitingForConcurrentSchemaChanges: func(stmts []string) {
 				for _, stmt := range stmts {
-					if wasBlocked && strings.Contains(stmt, "ADD COLUMN") {
+					if strings.Contains(stmt, "ADD COLUMN") {
 						addColumnBlockedCounter.Add(1)
 						return
 					}
@@ -161,6 +161,14 @@ func TestConcurrentDeclarativeSchemaChanges(t *testing.T) {
 		wg.Done()
 	}()
 
+	// The ADD COLUMN schema change must block.
+	testutils.SucceedsSoon(t, func() error {
+		if addColumnBlockedCounter.Load() == 0 {
+			return errors.New("waiting for concurrent schema change to block")
+		}
+		return nil
+	})
+
 	// Unblock the create index job.
 	continueNotif <- struct{}{}
 	wg.Wait()